Funded by the NSF CubeSat and NASA ELaNa programs, the Dynamic Ionosphere CubeSat Experiment (DICE) mission consists of two 1.5U CubeSats which were launched into an eccentric low Earth orbit on October 28, 2011. Each identical spacecraft carries two Langmuir probes to measure ionospheric in-situ plasma densities, electric field probes to measure in-situ DC and AC electric fields, and a science grade magnetometer to measure in-situ DC and AC magnetic fields. Given the tight integration of these multiple sensors with the CubeSat platforms, each of the DICE spacecraft is effectively a "sensorsat" capable of comprehensive ionospheric diagnostics. The use of two identical sensor-sats at slightly different orbiting velocities in nearly identical orbits permits the de-convolution of spatial and temporal ambiguities in the observations of the ionosphere from a moving platform. In addition to demonstrating nanosat-based constellation science, the DICE mission is advancing a number of groundbreaking CubeSat technologies including miniaturized mechanisms and high-speed downlink communications.

There has been a recent trend to increase capability and drive down the Size, Weight and Power (SWAP) of satellites. NASA scientists and engineers across many of NASA's Mission Directorates and Centers are developing exciting CubeSat concepts and welcome potential partnerships for CubeSat endeavors. From a "Telemetry, Tracking and Command (TT&C) Systems and Flight Operations for Small Satellites" point of view, small satellites including CubeSats are a challenge to coordinate because of existing small spacecraft constraints, such as limited SWAP and attitude control, and the potential for high numbers of operational spacecraft. The NASA Space Communications and Navigation (SCaN) Program's Near Earth Network (NEN) and Space Network (SN) are customer driven organizations that provide comprehensive communications services for space assets including data transport between a mission's orbiting satellite and its Mission Operations Center (MOC). This paper presents how well the SCaN networks, SN and NEN, are currently positioned to support the emerging small small satellite and CubeSat market as well as planned enhancements for future support.

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Preface A major research effort, the Global Tropospheric Experiment (GTE), has been initiated by the National Aeronautics and Space Administration (NASA) to study the chemistry of the global troposphere and its interaction with the stratosphere, land, and oceans. The first phase of GTE is aimed at developing and validating measurement techniques for trace species in tropospheric chemical cycles. It is designed to lead toward development and implementation of a cooperative research program involving NASA, scientists sponsored by the National Science Foundation, other government agencies, and research institutions abroad. The goal of the GTE is to understand the chemical cycles that control the composition of the global troposphere and its changes. The first major field program conducted as part of the GTE was denoted as Chemical Instrumentation Test and Evaluation (CITE 1). The principal thrusts of CITE 1 were aimed at evaluating advanced technologies for measurement of carbon monoxide (CO), nitric oxide (NO), and the hydroxyl radical (OH). An ad hoc scientific steering committee, established in 1982, recommended a three-step test and evaluation program involving a ground-based inter-comparison; an airborne intercomparison in the tropical troposphere, with particular attention to the boundary layer; and an airborne ]ntercomparison in the upper troposphere. This strategy was adopted in order to expose the measurement systems under evaluation to conditions expected to be encountered during future GTE field experiments. Island, Virginia, in July 1983. The airborne portions of CITE 1 were conducted onboard the NASA CV-990 aircraft platform. The first airborne mission focused on intercomparison in a tropical troposphere and was conducted in October 1983. The second airborne mission focused on the upper troposphere and was conducted in April 1984. The GTE/CITE 1 papers in this issue are devoted to a description of the activities and results from the ground-based intercomparison. Results from the airborne missions will be reported in a subsequent special issue of this journal.

A team of eight subject matter experts at NASA Goddard Space Flight Center (GSFC) completed a Lean Six Sigma project to identify process improvements for the compatibility test process for small satellites planning to use the NASA Near Earth Network (NEN). Ground station network compatibility testing is designed to reduce the risk to missions by resolving issues between the spacecraft's flight communication and navigation components and the ground systems prior to launch. Compatibility testing, which consists of a series of tests performed over a period of months and documented in reports, is an important step meant to prevent post-launch anomalies that could lead to expensive troubleshooting or mission failure. Compared to traditional missions, small satellite missions typically have a smaller budget and compressed schedules, which can result in small satellite projects' willingness to accept the risk associated with less comprehensive compatibility testing. Optimization and or refinement of the compatibility test process for small satellite missions could alleviate some of the pressures inherent with these factors. The goal of the Lean Six Sigma project was to develop alternative scalable methods of compatibility testing for small satellites. The Lean Six Sigma approach and the results of the project are reviewed in this paper.